Refuse burner apparatus

ABSTRACT

A subterranean burning chamber for burning refuse, which is covered by a frusto-conical metal shell, comprises a steel structure that is refractory lined and has hollow walls that are fluid-cooled. Means is provided for maintaining the chamber in place when buoyant forces are present.

0 United States Patent 1 91 1111 3,807,323

Watts Apr. 30, 1974 REFUSE BURNER APPARATUS 3,483,832 12/1969 B011 etal. .1 110/7 [76] Inventor: Ralph E. watts, 1313 Sewanee Dr. 3,452,6907/1969 Tarbox et al. ll0/7 Florence 2950] Primary ExaminerKenneth W.Sprague [22] Filed: Mar. 8, 1973 Attorney, Agent, or FirmSherman H.Barber; Olin E. [21] Appl No 339 337 Williams; 0scar B. Brumback 52 us.01. 110/8, 110/18 R [57] BSIRACT 51 1m. 01. F23g 5/00 A Subterraneanbuming chamber for burning refuse, [58] Fi ld f S h 110 7 R, 3 R, 8 C, 1R, which is covered by a frusto-conical metal shell, com- 1 10/13 Cprises a steel structure that is refractory lined and has hollow wallsthat are fluid-cooled. Means is provided [56] References Cit d formaintaining the chamber in place when buoyant UNITED STATES PATENTSforces are present 3,704,676 12/1972 Davies et al. 1. 110/8 5 Claims, 6Drawing Figures ffl //.9/ /97 0 //9 O i V95 i-fj iHHHHWHHH REFUSE BURNERAPPARATUS BRIEF SUMMARY OF THE INVENTION A refuse burner, in accordancewith the present invention, includes a subterranean, open-topped pit orchamber, that has hollow, fluid-cooled structural walls, the lower partof which are encased in concrete. The top of the pit or chamber iscovered by a frusto-conical shell with means at the top for collectingeffluent given off by burning material in the pit or chamber. Sucheffluent is recirculated into the bottom of the pit or chamber.

For a further understanding of the invention and for features andadvantages thereof, reference may be made to the following descriptionand the drawing which illustrates a preferred embodiment of equipment inaccordance with the invention which is suitable for practicing themethod of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is a schematic vertical sectional view of apparatus in accordancewith one embodiment of the present invention;

FIG. 2 is a plan view of the lower portion of the apparatus of FIG. 1;

FIG. 3 is a view along line lII-III of FIG. 4;

FIG. 4 is a view along line lV-IV of FIG. 3;

FIG. 5 is a view of the top portion of the apparatus shown in FIG. 1;and

FIG. 6 is a view along line VI--VI of FIG. 5.

DETAILED DESCRIPTION Referring to FIG. 1, a refuse burner 111, inaccordance with one embodiment of the present invention, comprises afrusto-conical shell 113 that surrounds and is located above asubterranean pit or burning chamber is generally rectangular in shape;is open topped; and is substantially entirely subterranean except for asmall portion at the top that extends a short distance above groundlevel. Such pit or burning chamber 125 is constructed in the mannershown generally in FIGS. l-4.

The frusto-conical shell 1 13 includes an angle iron or structural steelskeleton frame 115 that is covered, preferably, with aluminized sheetsteel shell 117. The skeleton frame may, of course, be made of any otherstructural members as preferred. Both the frame 115 and the shell 117are supported upon a circular concrete footing 119 disposed at groundlevel 121. The frusto-conical shell 113 is disposed above andsurrounding the subterranean pit or burning chamber 125.

The top of the frusto-conical shell 113 is shown in FIG. 5 and includesa cylindrical-shaped tubular member 123 wherein there is a conventionaldamper 124. The damper 124 may be of the vane or the shutter type, andit may be controlled in a conventional manner by a device that respondsto the temperature of effluent from burning waste products in the pit orburning chamber 125, or it may be operated manually, as preferred.

The pit or burning chamber 125 has four vertical side walls that areformed of outer 127 and inner 129 membranes, such as steel plating orheavy gauge sheet steel. These outer 127 and inner 129 membranes aremaintained in spaced-apart parallel relation by a plurality ofvertically arranged structural beams, such as I-I-beams 131. Each of theI-I-beams 131 is provided with a plurality of holes 133 in its web for apurpose that will be explained hereinafter.

The outer plating or membrane 127 is supported by verticallyspaced-apart, horizontally arranged I-beams and by short intercostalsections of vertically arranged structural angles 137. The wallmembranes or plating 127, 129 and the l-I-beams 131 are capped by ahorizontal cap plate 139, and they are supported upon a steel base plate141. Thus, the wall structure is hollow and fluid-tight, and the holes133 provide a passageway through the structural H-beams 131 for the flowof fluid, which may be air, in the wall structure to cool it.

The inner surface of the inner membrane or plating 129 is covered withan insulating material 143 that may be mineral wool or any othersuitable insulating material. Continguous with the insulating material143 is a lining of refractory bricks 145.

The bottom of the burning pit or chamber 125 is a resilient substance,such as a layer of sand 147, disposed over the bottom plating 141. Inthe sand layer 147 there are a plurality of grate boxes 149 that areeach provided with top grate 150. Each grate box 149 is connected to ariser 151 extending through the bottom plating 141 and joining a conduit153 below the bottom of the pit or burning chamber 125.

The lower one-third portion of the wall structure and the bottom of thepit or burning chamber 125 are encased in concrete 155. The concrete 155acts to prevent the hollow, bouyant wall structure of the pit or burningchamber 125 from moving upwardly whenever sub-surface water is presentin sufficient quantity to exert a bouyant force on the chamber 125.Anchor bolts 157 connect the side walls to the concrete, as shown. Ofcourse, other means than concrete may be used, if preferred, to provideenough extra weight in the structure to counteract bouyancy effects ofsubsurface water and the like on the chamber 125. Further, in regionswhere sub-surface bouyancy is not a consideration, the concrete 155 maybe omitted, but yet, in most instances, it may be installed to provide amore rigid support for the pit or burning chamber 125.

Associated with the pit or burning chamber 125 is a fly ash reinjectionsystem and a fluid-cooling system for the wall structure of the chamber125.

The fly ash reinjection system includes a collector cone 159, shown inFIG. 5, that is located just below the cylindrical-shaped tubular member123 at the top of the frusto-conical shell 113.

The collector cone 159, however, has a conical outer shell 161 thatmerges with a conduit 163 at its top, the conduit 163 being disposedhorizontally, as shown, through the shell 113, and directed downwardlyoutside the shell, as suggested. The collector cone 159 has a bottomportion 165, shown in FIG. 6, that is comprised of a structural grid 167made up of angles 169 to which are applied concentric annular plates171, so arranged that there are annular spaces 173 between adjacentconcentric annular plates; a center plate 175 is provided that is notannular in shape.

Conduit 163 connects with a centrifugal type fan 177, that is providedwith suitable motor drive 179, situated on a concrete slab or base 181adjacent the pit or burning chamber 125, as suggested in FIG. 2. Adischarge conduit 183 from the fan 177 connects to the header conduit153 (FIG. 1) with which the risers 151 and grate boxes 149 areassociated, as mentioned previously.

On the foundation or concrete slab 181, there is another fan 185,preferably of the centrifugal type, having a suitable motor drive 187,that receives ambient air through an intake 189 and that discharges theair under pressure into a plenum 191 through conduit 193. The plenum 191communicates, as shown in FIG. 1, with the hollow wall structure,supplying cooling fluid thereto.

The cooling fluid circulates through the hollow wall structure and thendischarges to atmosphere through an exhaust conduit 195; such conduitmay also pass through the shell 1 13 and terminate outside thereof, aspreferred.

Associated with the wall structure and the plenum 191 are a plurality ofnozzles 197 that extend slightly into the pit or burning chamber 125 andat a downward angle, about as shown in FIG. 1.

In operation, a quantity of wood and paper are placed on the floor ofthe pit or burning chamber, and they are ignited in a suitableconventional manner. A damper 46 at the top of the shell 113 is closedinitially and the fly ash reinjection system is activated to circulatethe effluent arising from the burning wood and paper. The effluent isrecirculated back into the chamber and, thereby, does not escape topollute the atmosphere.

The apparatus is quickly brought up to a working temperature asadditional waste wood products and other combustible material areintroduced into the pit or burning chamber, as desired, through a chute45, as suggested in FIG. 1.

When the chamber is at the working temperature and the walls have becomeheated, the cooling air fan is turned on to circulate cooling fluid inthe space 199 between the inner and outer walls. The cooling fluidmaintains the walls of the pit or chamber relatively cool, and duringthe burning process, waste wood and other combustible material areintroduced, more or less continually, into the chamber through thechute. In some instances a vehicle carrying such combustible material,may be admitted vto the shell, through an opening therein, (not shown)in order to dump its load into the chamber.

From time to time, or whenever it is deemed necessary or desirable,mobile equipment, such as a backhoe or other similar apparatus, may beadmitted to the shell through the opening for the purpose of removingash residue from the chamber. Such apparatus can easily approach closeenough to the edge of the chamber to quickly and effectively remove theash residue.

Those skilled in the art will recognize that when the walls of thechamber have reached a desired temperature, the fan, which connects tothe nozzles within the chamber, is operated. Air jetting from suchnozzles creates a curtain over the burning material and,'together withthe fly ash recirculating system, develops very high temperatures withinthe chamber. The temperature, about 2,000F, is well above that generallyregarded as desirable, which is around 800F, to obtain complete andeffective burning of waste material and the effluent produced.

From the foregoing description of one embodiment of the invention, thoseskilled in the art should recognize many important features andadvantages of it, among which the following are particularlysignificant:

Very high combustion temperatures, as high as about 2,000F, are obtainedin the combustion zone of the chamber of the apparatus of the invention.Since a temperature of only about 800F will produce clean burning ofwaste wood products, it is readily apparent that, at the hightemperature achieved in the apparatus of the invention, no smoke oreffluent escapes to the atmosphere;

Because the temperature in the subterranean chamber may be as high as2,000F, the refractory-lined walls, with insulating space in which fluidsuch as air under pressure circulates, can better withstand such a hightemperature than the thin shell portion above ground;

Because the distance between the combustion zone in the chamber and thecollection cone in the present apparatus is greater than that of burnerapparatus known from the prior art, the fly ash cools down somewhat, andthe upward, thermally-generated velocity of the fly ash in the presentapparatus is much lower than that developed in prior art burnerapparatus. These advantages result in less wearing of the conduits ofthe present fly ash reinjection system;

That batch feeding of waste wood products and other consumable materialinto the chamber is readily afforded, since there is a large access doorand opening in the shell of the apparatus;

That ash removal from the chamber can also be readily accomplished,since mobile ash removal equipment is easily moved into and out of theshell through the access door and opening;

Since almost the entire burning chamber is below ground level, a uniformtemperature profile down the wall of the chamber is effected, and nothermal shocks are set up from water or wind, and the like, or from anywater seepage below ground level.

Flooding of the burning chamber is prevented, since it is protected bythe above-ground shell;

The structural characteristics of the burning chamber, particularly thefluid-cooled walls andthe resilient sand floor, promote long life inservice with very little loss in burning time or expense; and

The resilient floor in the chamber absorbs highimpact loads from batchfeeding of large items such as pole cut-offs, stumps, scrap wood, andthe like; the sand floor also is an effective insulating medium toprevent spalling of the concrete base.

Although the invention has been described herein with a certain degreeof particularity, it is understood that the present disclosure has beenmade only as an example, and that the scope of the invention is definedby what is hereinafter claimed.

What is claimed is:

1. In a refuse burner apparatus, the improvement comprising:

a. a hollow wall structure comprised of inner and outer spaced-apartplates with structural members disposed therebetween to maintain suchplates in place, said wall structure being substantially entirely belowground level;

b. a layer of insulating material disposed on the inner wall plate;

c. a layer of refractory material convering said insulating layerandforming the inner surface of the walls of said burner apparatus;

d. a cap plate covering the top of said wall structure;

e. a bottom plate on which said walls rest thereby forming a support forsaid structure and the bottom of said apparatus;

f. a plenum chamber communicating with said hollow wall structure forintroducing fluid thereinto to cool said wall structure;

g. means for introducing a cooling fluid into said plenum chamber; and

h. means for flowing said cooling fluid out of said wall structure.

2. The invention of claim 1 including:

a. a frusto-conical shell surrounding and covering the burning apparatusand having therein:

b. a collector for effluent emitted by burning refuse in said apparatus,said collector being located adjacent the top of said shell,

c. said collector comprising a grid that has spaces through which saideffluent passes; and

d. conduit means connecting said collector and a fan that receives sucheffluent and urges it into and through grate boxes in said bottom plate.

3. In a refuse burner apparatus, the improvement comprising:

a. a hollow wall structure comprised of spaced-apart inner and outermembranes forming the periphery of said apparatus with meanstherebetween for maintaining said membranes in spaced-apart relation,said wall structure being substantially entirely below ground level;

b. a cap plate covering the top of said wall structure;

c. a bottom plate on which said walls rest thereby forming a support forsaid structure and a bottom closure for said burner apparatus; and

d. means coacting with said wall structure for resisting upward forcesacting on said apparatus.

4. The invention of claim 3 wherein:

a. said means coacting with said wall structure comprises a jacket ofconcrete affixed to said wall structure.

5. The invention of claim 3 including:

a. a plenum communicating with said hollow wall structure forintroducing a cooling fluid into said wall structure; and

b. means for introducing a cooling fluid into said plenum.

2733 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,807,323 D d April 30, 1974 Inventor(s) Ralph E. Watts It is certifiedthat error appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

? The name and address of the Assignee should be printed on the face ofthe patent as shown below:

Assignee: Koppers Company, Inc.

a Corporation of Delaware Signed and sealed this lsti day of October1974,

(SEAL) 'Attest:

McCOY M. GIBSON JR. c. MARSHALL DANN Attesting Officer Commissioner ofPatents

1. In a refuse burner apparatus, the improvement comprising: a. a hollowwall structure comprised of inner and outer spacedapart plates withstructural members disposed therebetween to maintain such plates inplace, said wall structure being substantially entirely below groundlevel; b. a layer of insulating material disposed on the inner wallplate; c. a layer of refractory material convering said insulating layerand forming the inner surface of the walls of said burner apparatus; d.a cap plate covering the top of said wall structure; e. a bottom plateon which said walls rest thereby forming a support for said structureand the bottom of said apparatus; f. a plenum chamber communicating withsaid hollow wall structure for introducing fluid thereinto to cool saidwall structure; g. means for introducing a cooling fluid into saidplenum chamber; and h. means for flowing said cooling fluid out of saidwall structure.
 2. The invention of claim 1 including: a. afrusto-conical shell surrounding and covering the burning apparatus andhaving therein: b. a collector for effluent emitted by burning refuse insaid apparatus, said collector being located adjacent the top of saidshell, c. said collector comprising a grid that has spaces through whichsaid effluent passes; and d. conduit means connecting said collector anda fan that receives such effluent and urges it into and through grateboxes in said bottom plate.
 3. In a refuse burner apparatus, theimprovement comprising: a. a hollow wall structure comprised ofspaced-apart inner and outer membranes forming the periphery of saidapparatus with means therebetween for maintaining said membranes inspaced-apart relation, said wall structure being substantially entirelybelow ground level; b. a cap plate covering the top of said wallstructure; c. a bottom plate on which said walls rest thereby forming asupport for said structure and a bottom closure for said burnerapparatus; and d. means coacting with said wall structure for resistingupward forces acting on said apparatus.
 4. The invention of claim 3wherein: a. said means coacting with said wall structure comprises ajacket of concrete affixed to said wall structure.
 5. The invention ofclaim 3 including: a. a plenum communicating with said hollow wallstructure for introducing a cooling fluid into said wall structure; andb. means for introducing a cooling fluid into said plenum.